Electronic communication may be conducted employing a variety of formats including direct telephonic voice communication, facsimile document communication, electronic mail communication, and telephonic voice message communication. Facsimile document communication and electronic mail communication may be characterized as document-based and the other two formats as voice-based.
Direct telephonic voice communication is unique among these formats in that it requires simultaneous participation by all parties. In many business situations, the requirement for simultaneous participation is unnecessary, disruptive, time-consuming, and often impossible because a called party telephone is busy or the party is otherwise unavailable. As a consequence, nonsimultaneous communication formats, such as facsimile document communication, electronic mail communication, and telephonic voice message communication are becoming preferred over direct telephonic voice communication for many situations.
Because ever-increasing volumes of information are being transmitted by the different nonsimultaneous communication formats, document store and forward systems have been developed to improve the efficiency, cost-effectiveness, and useability of facsimile document and electronic mail communications formats. Document store and forward systems implement features such as delivering a single communication to multiple parties, deferring communication delivery to a reduced rate time period, deferring a communication delivery until business hours in a different country or time zone, forwarding a communication to a predetermined address, returning a communication delivery notification, identifying and/or authenticating a particular communication, and delivering a particular communication according to a delivery priority.
Document-based store and forward systems, such as one described in U.S. Pat. No. 5,014,300 for METHOD AND APPARATUS FOR ACCESSING A FACSIMILE STORE AND FORWARD NETWORK, have been developed for compatibility because facsimile machines and electronic mail systems are based on digital communication technology that is intended for transmitting messages among widely separated locations, often across international boundaries. The communication receiving facsimile machines and computers are manufactured by a variety of manufacturers according to internationally accepted features, standards, and communication protocols that were developed to satisfy a common need.
In contrast, voice-based store and forward systems have not necessarily been developed for compatibility because prior voice mail systems were primarily intended for transmitting analog messages among users sharing a common voice message system, such as one installed in a corporation. Therefore, voice mail systems have been manufactured by a variety of manufacturers, each adopting a proprietary set of features and communication protocols that were developed to satisfy the needs of each manufacturer.
Clearly, voice-based store and forward systems would benefit from many of the features and capabilities of document-based store and forward systems. However, the incompatible protocols employed by different voice message systems hinder the development of all such capabilities. Moreover, because of the distances and complexities of telecommunications networks, voice messages transmitted in such networks are subject to transmission delays and costs that render impractical features such as voice signature authentication of a destination voice message address.
For example, virtually all voice message systems return to an originator a recipient's voice signature to prevent inadvertently sending a voice message to an incorrect recipient. The voice signature is typically the recorded name of the recipient user spoken in the user's voice, for example, "John Smith." In prior non-networked voice message systems, the name, voice signature, and other information associated with every user is recorded in a "user file." When an originator enters a recipient voice message address, the voice message system accesses the user file and returns the associated voice signature to the voice message originator to authenticate the entered voice message address.
Unfortunately, in a networked voice message system, when an originator enters a recipient voice message address that is at a remote destination, the originating voice message system cannot readily access the destination user file without encountering undue telecommunications-related delay and expense. The destination user file is rendered completely inaccessible if the voice message is marked for deferred delivery or for grouped transmission with other voice messages. Moreover, local duplication, updating, and storage of the myriad of destination user voice signatures is impractical. For example, the Octel VMX-5000 networked voice message system stores duplicate user files in each system and updates all of them in response to user changes. Such duplication requires a heavy and ongoing database maintenance commitment. To circumvent the database maintenance problem, the AT&T Intuity voice message system employs a centralized user file database facility. However, this approach requires time consuming network wide intercommunications, which unacceptably delays returned voice signatures.
What is needed, therefore, is a communication method suitable for intercommunicating among and rendering compatible the features and authentication methods of multiple disparate voice-based message systems and voice message store and forward units distributed across a geographically distributed telecommunications network.